Hollow rivet having two internal shoulders



March 17: 1959 J'. K. BARRYl ETAL y$877,682' K HOLLOW RIVET HAVING TWO INTERNAL SHULDERS Filed Nov. 12, 1954 2 Sheets-Sheet l BY/Uei mf JAP wg d i-V l 3d ATTORNEYS.

J. K. BAP-:RY ETAL 2,877,682 HoLLow RIVET HAVING Two INTERNAL sHouLDERs Filed Nov.'12, 1954 Marh 17, 1959 2 Sheets-Sheet 2 MMM A TT ORNE YS.

HOLLOW RIVET HAVING TWO INTERNAL SHOULDERS Ilohn K. Barry, Philadelphia, and Michael R. Tnoz'zo,

Prospect Park, Pa., assignors to South Chester Corporation, Chester, Pa., a corporation of Delaware Application November 12, 1954, Serial No. 468,272 6 Claims. (Cl. 85-40) This invention relates to fastening devices. lt/lore spe: cically, it is concerned with a fastening device of the general type disclosed in U. S'. Patent 2,668,468 granted to Howard A. Flogaus on February 9, 1954 ordinarily' known as blind rivets, usefulA in securing -together structural elements such as metallic plates, panels of wood, plastic sheets and the like, and--consisting of a headed tubular main component with a split shank, and an expander pin adapted to be driveninto "said main component, after insertion of the shank of the latter into registering holes in the parts to be united, and outwardly expand or spread the protruding Idistal split segmental end or prong portions of the'sh The chief aim of our invention'is to lprovide .a fas, tening device ofthe kind referred to capable of securing together a plurality of structural elements whose aggregate thickness mayvary' over a wide range, without danger of overstressing `the shank ofthe main component, cracking or breaking the prong ends incident to bendingand cross sectional reformation or in any way' weakening the device.

A further aim of our invention is to provide a fastening device of the kind referred to of which the'main component is so proportioned that but a minimum of effort or force is required to drive home the expander pin to fix the device in permanent relation to the elements connected thereby.

Another object of our invention is to yattain the foregoing'advantages in a fastening device which is simple in Iconstruction, and which lends itself to ready fabrication in quantity `at small cost.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein:

Fig. 1 ,is a perspective view showing the twoI component parts of a fastening device conveniently embodying our invention in one form.

Fig. 2 shows the main component of the device in axial or longitudinal section.

Fig. 3 shows the two parts assembled in readiness in preparation for the use of the device.

Figs. 4, 5 and 6 are fragmentary sectional views showing the manner in which plural structural elements of different aggregate thicknesses are permanently secured together by the device of Fig. 1.

Figs. 7, 8, 9, Iand llshow, in longitudinal section, various modifications of themain component of the device; and

Figs. 12, 13, 14, andv 16 show different alternative forms of the associated component or spreader pin.

With more retailed reference, first more particularly to Figs. 1-3 of these illustrations, the form of my improved fastening device there depicted, comprises a tubular main component 1 having a rounded head 2 and a cylindrical shank 3. The shank 3 is diametrically split longitudinally as at 4, inwardly from its distal end through a portion of its length, the slit having in this instance straight continuous sides and being tapered inwardly from its mouth and 8 maybe spherically or end. Instead of but a single slit, the shank of the com-- ce. ,Patented Mar. 17, 1959.,

ponent 1 may be provided with additional such slits if, desired. The large entrant portion 5 of the bore in the component 1 terminates at a point medially ofthe length A of the slit, i. e., at a point somewhere between the ends of said slit 4. The diametrically-reduced smaller intermediate portion 7 of the bore in the main component 1, in turn, terminates short of the distal end of the shank 3. The remaining end lportion of the bore in the shank 3 r of the component 1 may be of the same diameter as that.

of the entrant end. As a result of this construction, therel` are formed on the prongs defined by the slit 4, shoulders 6 and 8 in spaced relation, and inwardly-projecting lugs 9 fronted by the latter shoulders. Theshoulders at 6 parabolically rounded as shown. Y

The device further comprises an expander pin 1l)y which is cylindrical and substantially of the same diam-l eter as the entrant end 5 of the bore in the component 1, and which is rounded as at 11 at one end. rIn prepa-k ration of the device for the market, the. pin 10 is ordi-r narily pre-assembled with the component 1 as in Fig. 3.

In the use of the device to secure together two relatively thin structural elements Such as plates or sheetsV 12 and 13 for example as in Fig. 4, the shank 3 of the f component 1 is inserted into registering holes in said plates j until stopped by the head 2. With the device so placed,

the pin 3 10 is driven inward of the component 1 by r means of a hammer or a suitable power tool, applied tol its at end. As the pin 10 is soldriven the surrounding;

split portion of the shank3 of the component 1 may be rst expanded laterally within the hole in the element 13 by action of the rounded end of the pin 10 as the latter is forced into and through the small portion 7 of the bore past the shoulders 6 with attendant progressive displacement of the material of the shank in-this region and partial outward expansion' of said prongs. As the pin 10 continues, in its advance, it acts upon the shoulders 8 on the prongs of the shank 3 and gradually spreads the protruding end portions of said prongs apart radially at complementary angles as iny Fig. 4, the points of bending being in the plane of thefexposed face of the plate 13. Slight enforced elongation and lateral expan sion of the shank of the componentvl takes place, 'of course, with attendant flow of the material and corre sponding change in the cross sections ofthe segmentsor prongs of the split at the regions of the bends, this is A controlled within the proportional limit of the metal. As`

a result it will 'be seen that. the elements 12 and 13 are and the device securely lodged within them against the possibility of subsequent displacement.

- drawn together and tightly and rigidly united permanently,A

In Fig. 5, where the aggregate thickness of the structural elements or plates 14 and 15 is somewhat greater,

the protruding end portions or prongs of the shank 3 of the component 1 are bent outward radially at the same complemental angles as in Fig. 4, about axes in the plane of the exposed face of the plate 15, by action of the rounded end of the yspreader pin 10 upon the shoulders 6 and 8. In this instance, it will Ibe noted that the pro-f jections 9 have been transformed into ,solid wedge sections by enforced linear liow and outward displacement@ of the metal ofthe split segments, or prongs of the' shank 3.

When the device is used to secure together structural members or plates 16 and 17 whereof the combined thickness is still greater as in Fig. 6, the protruding end portions of the prongs of the shank 3 of the component 1 are spread apart to the same extent and bent outwardly at approximately the same complementary angles about 

